Method of controlling a buoyancy system for an aircraft, and a control system implementing said method

Abstract

A method of controlling a buoyancy system for an aircraft includes: determining the roll angle φ and the pitching angle θ of the aircraft; verifying whether −φ R <+ R and whether −θ R <θ<+θ R , where φ R and θ R are predefined limit angles; if at least one of the angles φ and θ is no longer in its above-defined respective range, activating an automatic trigger of the buoyancy system; if the angles φ and θ are in their above-defined respective ranges, determining the altitude A of the aircraft; inhibiting the automatic trigger if A >A R , where A R is a predefined limit altitude; and if A R ≧A, and if at least partial immersion of the aircraft has been detected, activating the automatic trigger.

What is claimed is: 
     
       1. A method of controlling a buoyancy system for an aircraft, the buoyancy system including manual trigger means and automatic trigger means and a controller configured to cause floats to inflate in response to either trigger means being activated, the method comprising taking account of at least one attitude parameter of the aircraft in order to control the automatic trigger means, and the method further comprising:
 a) determining, with an inertial sensor, the roll angle   and the pitching angle θ of the aircraft; 
 b) verifying, with an analyzer in communication with the inertial sensor, whether    
 and whether
   −θ R <θ<+θ R  
 
 
 where   and θ R  are predefined limit angles; 
 c) if at least one of the angles   and θ is no longer in its above-defined respective range, activating the automatic trigger means to thereby cause the controller to cause the floats to inflate; 
 d) if the angles   and θ are in their above-defined respective ranges, determining, with an altimeter, the altitude A of the aircraft; 
 e) inhibiting, with an inhibitor in communication with the altimeter, the automatic trigger means if A>A R  and returning to step a), where A R  is a predefined limit altitude; and 
 f) if A R ≧A and if at least partial immersion of the aircraft has been detected with an immersion detector, activating the automatic trigger means to thereby cause the controller to cause the floats to inflate, else returning to step a). 
 
     
     
       2. The method according to  claim 1 , further including manually priming the buoyancy system. 
     
     
       3. The method according to  claim 1 , further including automatically priming the buoyancy system when the aircraft is overflying the sea and when the speed of the aircraft is less than a determined speed Va. 
     
     
       4. The method according to  claim 1 , comprising implementing the steps a) to f) at a determined frequency of 1 Hz or 2 Hz, or continuously. 
     
     
       5. An emergency buoyancy system for an aircraft, the system comprising:
 manual trigger means and automatic trigger means including an immersion probe; 
 a buoyancy controller connected to the manual trigger means and to the automatic trigger means and controlling inflation of floats housed in the aircraft, inflation being provided by cylinders of gas under high pressure, in response to either of the trigger means being activated, said controller also being connected to at least one electrical power supply; 
 an inertial sensor configured to determine the roll angle   and the pitching angle θ of the aircraft; 
 an analyzer configured to verify whether   and whether −θ R <θ<+θ R , where   and θ R  are predefined limit angles; 
 wherein the automatic trigger means is configured to activate to thereby cause the controller to cause the floats to inflate when at least one of the angles   and θ is not in its above-defined respective range; 
 an altimeter configured to determine the altitude A of the aircraft when the angles φ and θ are in their above-defined respective ranges; and 
 an inhibitor configured to inhibit the automatic trigger means when A>A R , where A R  is predefined limit altitude; 
 wherein the automatic trigger means is further configured to activate to thereby cause the controller to cause the floats to inflate when A R  ≧ A and at least partial immersion of the aircraft has been detected by the immersion probe. 
 
     
     
       6. The system of  claim 5  wherein the aircraft is a rotorcraft or helicopter type aircraft.